Water-tube boiler.



A. D. PRATT.

WATER TUBE BOILEEL APPLICATION FILED JULY s, 1912.

1,05 1,91 3. Petentea Feb. 4, 1,913.

@/m Mw. ZMW-M across andv around the tubes, as'indicated by A TED sTA'rEs PATENT oEEioE.

,ARTHUR D'. PRATT, OF NEW YORK, N; Y., ASSIGNOR T0 THE BABCOCK & WILCOX COM- lIANY, 0F `BJYONNE, NEW JERSEY, A CORPORATION 0F -NEW JERSEY. y

WATER-TUBE BOILER.

Specification of Letters Patent.

Patented Feb. 4, 1913.

Application led July 3, 1912. Serial No. 707,420.

To aU whom, t may concern:

Be it known that I, ,ARTHUR D.' PRA'IT, a citizen of the UnitedV States, residing at New York city, borough of Manhattan, in

lthe county of New York andl State of New symmetrically arranged above a common fuel and combustion chamber extending from one side of the boiler to the other. The disposition of the 'boiler units provides an A-shaped combustion chamber of large volume, separate portions of the gases being directed from the central combustion chamber in independent streams tow'ard the outlet tlues.

The invention will be understood by reference to the accompanying drawing which is a longitudinal section through a boiler embodying the same;

The present design comprises two units each consisting of a bank of inclined'water tubes, the tubes 1 of the left hand bank being expanded into lower and upper headers 2 and 3, and Vthe tubes 4 ofthe right 'hand unit'being expanded into lower. andupper headers 5 and 6. These headers extend transversel of thev boiler from one side wall of the settmgto the other s'idewall. The

uptake ends of the lowermost rows of tubesare expanded into' a transverse 'drum 23 as hereafter explained. s

Each bank is divided by transverse baiiies 'l and 8, the baiies 7 rising from baiiles 9 extending from the lower :headers toward the,

upper to the first pass, thus providing a plurahty of transverse, passes for the gases the arrows. The u per-'headers 3 are connected by short vertical pipes l0 with a lon-` gitudinal steam and water drum 1l, and the.

latter isconnected with the lower headers by pipes 12. The u per headers 6 are connect ed by shortvertical pipes l3with a longitudinal steam and water drum 14, and the latter is connected with the lower headers 5' by pipes 15. Walls 8 extendA :from the .transverse baiiles 8- to the drums l1 and 14,

second passes, are placed |superheaters 16 ignition arches'21 and 22.

and 17 of any approved type. The form i l shown comprises two transverse boxes con nected by U-shaped tubes, the upper boxes being connected to the steam space-of. the corresponding drum.

*The boiler units above described are suspended over `a common furnace extending from the front to the rear of theb'oiler. In theA design shown the furnace is divided along its center b a lowwall 18 extending from one sidewal to the other. This wall serves as a rear wall of the two fuel bed sections, in this instance, two chain grate stokers 19 and 2O of any approved construction, and operated independently of each other, one from the front and the other from the rear of the setting. The mud drums of the boiler are above and protected bythe t The two boilerunits are disposed symmetrlcally with reference to the centerline of the fuel chamber, and so disposed relativeto each other that the upper headers 3 and-6 converge toward y.each other downwardly, and at then lower ends may be nippled to a transversedrum` 23, or they may not be directly connected to lthe same. The uptake ends of the lower rows of the banks of tubes,

' three rows being so shown, those which are exposed'to the direct radiant heat from the fire, are expanded into said drum 23. The latter'extends from one side wall ofthe set-l =ting to the other and this arrangement provides an A-shaped combustion chamber 24 common to both unitsL- This combustion chamber is closed at the apex by the drum 23 and open for the escape ott-the gases along lthe up er portions of its inclined sides, the

4 owing across and around the tubes through the three transverse passes to the l e two outlet-.dues 25 and 26.,

gases 'The drum 23 is connected by pipes 27 with the drums 11 and 14 so that the 'steam gen* said'pipes 27 into the' drums 11 and 14 and yerated in thelower tubes of the two units, vwhich come in contact with the direct radiant heat from the lire, is discharged thro-ugh' does not have to travel throu h the upper gheaders.' A diaphragm 28 divldes drum 23 into two separate chambers so that the steam and water clrculation of the right unit is independent of that of the left unit. Additionally the presence of the drum 23 insures against the burning 'of .the lower ends of the upper headers.

With the inclination of the boiler units, and the arrangement above described, providing an -Shaped combustion chamber, the character ofthe combustion may be maintained constant from one side of Athe boiler to the other, and the loss often experienced through a stream or lane ofV excess air or unconsumed combustible gases passing through the boiler andescaping to the stacks will be avoided. Any irregularity in the composition of the gases from the front-to the rear of the furnace disappears beforethe gases pass from the upper Ipart of the combustion chamber resulting in a more. etticient and economical operation.4 f j The baliies 9 instead of being supported on the second or third -ot the lower rows of' tubes may be supported on the lowermostrow, extending romthe lower headers to the rst pass, as shown in a companionv application Serial No. 707,419, filed July 3, 1912;-

It may be desirable to connect the water boxes 29 below the wall 18 with the circulation. For such purpose I have shown thein connected by pipes 30 and 31 with the transverse drum 23 and the lower headers respectively.

What I claim is: 1. In a water tube boiler, the combination of two units each comprising a bank of inclined water tubes, lower and upper headers into which said tubes are expanded, said units .being so disposed that the upper headers converge toward each other downwardly, whereby' an A-shaped combustion chamber is" formed between the units, a transverse drum at the apex of the combustion chamber to which the lowery ends of said upper headers are nippled, and a furnace chamber com-mon to said units.

2: In a water tube boiler, the combination of two units each comprising a bank of inclined water tubes, lower and upper headers into which said tubes are expanded, said units being so disposed that the upper headers converge toward each other downwardly, whereby an A-shaped combustion.

chamber is formed between the units, a transverse drum at the apex of the combustion chamber to which the lower ends of said upper headers are nippled, 'a vertical longitudinal diaphragm inl said transverse drum, and a furnace chamber common to said units. i

3. In a water tube boiler, the combination oftwo units each comprising a bank of inclined water tubes, lower andv upper 4headers' into which said tubes are expanded, said units being so disposed that the upper headers converge toward each other downwardly,

ywhereby an -shaped combustion chamber is formed between the units, a transverse drum at the apex of the combustion chamber to which the lower ends of said upper headers and the uptake ends of the lower rows of tubes of said banks are connected, and a furnace chamber common to said units.

4. In a water tube boiler, the combination of two units each comprising a bank of inclined water tubes, lower and upper headers into which said tubes are expanded, said units being so disposed that the upper headers converge toward each other downwardly,

whereby an A-Shaped combustion chamber 1s formed between the units, a transverse drum at theapex'of the combustion chamber to vwhich the lower ends of such upper headers are nippled, a steam' and water drum for each unit, and pipes connecting said transverse drum and said steam and water drums., and a furnace chamber common to said units.

5.. In a water tube boiler, the combination of two units each comprising a bank of inclined water tubeslower and upper headers into which said tubes are expanded, said units being so disposed that the upper headers converge toward each other downwardly,

whereby an it-shaped combustion chamber is formed between the units, transverse bafiies dividing said banks into a plurality of passes beginning at the steamuptake ends, a transverse drum `at the apex of the combustion chamber to which the lower ends of ,said upper headers are nippled, and a Vfurnace chamber common to said units.

6. In a water tube boiler, the combination of two units each comprising a bank of inclined water tubes, lower and upper headers into which said tubes are expanded, said units being so disposed that the `upper headers converge toward each other downwardly, whereby an A-shaped combustion chamber is formed between the units, transverse baiies dividing said banks into a plurality of passes beginning at the steam uptake ends, baiies extending from the lower headers upwardly vto the first pass, a transverse drum at the apex ofthe combustion chamber to which the lower ends of said upper headers are nippled, and a furnace chambercolnmon to said units.,

Iny testimony whereof I have hereunto signed my name in the presence of two subscribing witnesses.

ARTHUR D. PR ATT.

Witnesses:

' M. E. MCNINCH,

CHARLES S. Jonas. 

